Surgical cutting instruments in which an elongated inner member (i.e., solid shaft or tube) is rotated within an elongated outer tubular member have become well accepted in surgical procedures where access to the surgical site is gained via a narrow portal or passage. Typically, the outer tubular member includes a distal end forming an opening defining a cutting window or port, and the inner member includes a distal end forming a cutting tip for cutting bodily tissue at the window. Proximal ends of the inner and outer members are commonly secured to hubs that, in turn, are attached to a powered handpiece for rotating and/or oscillating the inner member relative to the outer tubular member. The cutting tip of the inner member can have various configurations specific to the surgical procedure in question (e.g., cutting, resecting, abrading, shaving, etc.), with the cutting window being suitably configured to cooperate with a particular configuration of the cutting tip.
Often, the inner member is not solid but tubular so that the loose tissue resulting from a cutting, resecting, or abrading procedure can be aspirated through the hollow lumen of the inner member. With specific reference to ENT (i.e., ear, nose, and throat) applications, such as sinus surgery, adenoidectomy, laryngeal surgery, etc., extremely sharp, micro-resecting blades or cutting tips are typically employed to effectuate the desired procedure.
Use of such surgical cutting instruments generally entails delivering the cutting window/cutting tip to the target site and positioning the cutting window such that the cutting tip is “exposed” to the desired tissue. Once the desired tissue has been treated, other tissue may be addressed, by positioning the cutting window to expose the cutting tip to such other tissue. A variety of types of tissue may be the subject of a given surgical procedure. Thus, while upon initial placement at the target site the cutting window may be the optimum design for a first portion of the procedure, tissue at a different location will also require removal, and such tissue may or may not be the same type as previously encountered. If not, the instrument may no longer be the optimum design for the type of tissue newly presented to the instrument.
In addition, and regardless of tissue type, obstruction of the surgical cutting instrument clearly is a problem. In particular, some types of tissue (e.g., thin bone) are prone to cause such surgical instruments to clog more often than other types of tissue, or (perhaps more importantly) more often than the surgeon desires (i.e., never). Such clogging generally may require removal of the cutting window/cutting tip from the target site, and either cleaning out the window or replacing some or all of the apparatus entirely. This extends the surgical procedure, which is undesirable.
If the surgical cutting instrument is used with an image guided surgery (IGS) system, additional concerns may arise. In particular, IGS generally entails registering the cutting window/cutting tip once deployed to the target site. Following reinsertion of the cutting instrument, the cutting window/cutting tip must be re-registered relative to the IGS system, further extending the surgical procedure.
Compounding the clogging problem is the reality that different types of tissue have different propensities to clog a given apparatus. It is generally undesirable to require a surgeon to use as many configurations of cutting tip/cutting window as there are types of tissue encountered in a given procedure. Similarly, it is generally undesirable to require a surgeon to use as many configurations of cutting tip/cutting window as there are types of procedures likely to be encountered within the realm of ENT surgery (note the wide variety of procedures listed above).
Thus, while surgical cutting instruments continue to be extremely useful, the need to prohibit clogging of the cutting window has not been fully addressed, particularly when considering the wide variety of tissue types and procedures involved. Therefore, a surgical cutting instrument designed to reduce clogging, despite being exposed to a variety of tissue types and/or a variety of procedures, is very much needed.